Activation analysis of the European DEMO divertor with respect to the different breeding blanket segmentation

Abstract

• Neutronic analysis of European DEMO fusion reactor single-null type divertor cassette. • Divertor neutron activation calculation with three different integrated breeding blanket modules (HCPB, WCLL MMS, WCLL SMS). • Neutron activation in divertor functional layers (radionuclide and reaction analysis). Neutron activation is an unavoidable process in large scale fusion devices operating with deuterium and tritium fuels. Neutron activation leads to the production of radioactive materials. Activated materials can generate heat and ionizing radiation in their environment. Consequently, values of activation characteristics need to be determined in order to ensure safety and performance of the fusion devices. In this work activity and decay heat inventories for the DEMOnstration power plant (DEMO) 2015 baseline model divertor were calculated. Operation scenario of 1898 days was considered as well as three different breeder blanket configurations of DEMO reactor: single-module segmentation water cooled lithium lead (WCLL SMS), multi-module segmentation water cooled lithium lead (WCLL MMS) and helium cooled pebble bed (HCPB). Divertor model is divided into 62 segments and 4 layers with different material compositions. Neutron transport and activation inventory calculations were performed respectively with MCNP and FISPACT codes. In addition to activation calculation results, divertor radionuclide analysis is also presented in this work.